#
score = eval(input('请输入成绩分数：'))
if score >=60:
   print("成绩以及格")

score = eval (input("请输入成绩分数:"))
if score<60:
   print("成绩不及格")
if 60 <=score<80:
   print("成绩一般")
if 80 <=score<=90:
   print("成绩良好")
if 90<score<=100:
   print("成绩优秀")

score = eval(input("请输入成绩分数："))
if 60<=score:
   print ("成绩已及格")
   if 90<=score<=100:
      print("成绩很好")

score = eval(input("请输入成绩分数："))
if score>=60:
   print("成绩及格")
if score < 90:
   print("成绩一般")
else:
   print("成绩很好")

score = eval(input("请输入成绩分数："))
if score>=60:
   print("成绩及格")
   if score >= 90 :
       print("成绩很好")
   else:
        print("成绩还行")
else:
    print("成绩不及格")
    if score >= 30:
       print("成绩极差")
    else:
         print("成绩较差")

a=input("数字")
b=input("数字")
c=input("数字")
if a+b>c and a+c>b and b+c>a:
   print("是合格三角形")
else:
   print("不是合法三角形")

a=eval(input("输入年份"))

   def is_triangle(a, b, c):
        return a + b > c and a + c > b and b + c > a
    print(is_triangle(3, 4, 5))
    print(is_triangle(5, 12, 13))

year = int(input('输入年份'))
if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):
    print(year, "是闰年")
else:
    print(year, "不是闰年")